Hepatitis C Virus Tests

Test Overview

Hepatitis C
virus (HCV) test is a blood test that looks for the genetic material (RNA) of the virus that causes hepatitis or for the proteins (antibodies) the body makes against
HCV. These
proteins will be present in your blood if you have a hepatitis C infection now
or have had one in the past. It is important to identify the type of hepatitis
virus causing the infection, to prevent its spread and choose the proper
treatment.

HCV is spread
through infected blood.

Anti-HCV antibody tests
look for antibodies to HCV in the blood, indicating an HCV infection has
occurred. This test cannot tell the difference between an acute or long-term (chronic)
infection. The enzyme immunoassay (EIA) may be the first test done to detect
anti-HCV antibodies.

HCV RIBA is another test that detects antibodies to HCV. This test can tell whether a
positive result was caused by an actual HCV infection or whether the result was
a
false-positive. This test may be done to double-check
a positive EIA test result.

HCV genetic
material (RNA) testing uses polymerase chain reaction (PCR) to identify an
active hepatitis C infection. The RNA can be found in a person's blood within 2 weeks after exposure to the virus. HCV RNA testing may be done to
double-check a positive result on an HCV antibody test, measure the level of
virus in the blood (called viral load), or show how well a person with HCV is
responding to treatment.

HCV quantitative
test (also called viral load) is often used before and during treatment to find
out how long treatment needs to be given and to check how well treatment is
working.

HCV viral genotyping is used to
find out which genotype of the HCV virus is present. HCV has six genotypes, and
some are easier to treat than others.

There is no vaccine available to prevent hepatitis
C.

Why It Is Done

Hepatitis C virus testing is done
to:

Find out if a hepatitis C
infection is the cause of abnormal liver function tests.

Screen people (such as doctors, dentists, and
nurses) who have an increased chance of getting or spreading a hepatitis C
infection.

Screen people born from 1945 to 1965. People in this age group are more likely to have hepatitis C and not know it.1, 2

Identify the type of hepatitis C virus causing
the infection.

How To Prepare

You do not need to do anything before
you have this test.

Talk to your doctor about any concerns you
have regarding the need for the test, its risks, how it will be done, or what
the results will mean. To help you understand the importance of this test, fill
out the
medical test information form(What is a PDF document?).

How It Is Done

The health professional taking a sample
of your blood will:

Wrap an elastic band around your upper arm to
stop the flow of blood. This makes the veins below the band larger so it is
easier to put a needle into the vein.

Clean the needle site with
alcohol.

Put the needle into the vein. More than one needle stick
may be needed.

Attach a tube to the needle to fill it with
blood.

Remove the band from your arm when enough blood is
collected.

Put a gauze pad or cotton ball over the needle site as
the needle is removed.

Put pressure on the needle site, and then
put on a bandage.

How It Feels

The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
pinch.

Risks

There is very little chance of a problem from
having a blood sample taken from a vein.

You may get a small bruise at the site. You
can lower the chance of bruising by keeping pressure on the site for several
minutes.

In rare cases, the vein may become swollen after the
blood sample is taken. This problem is called phlebitis. A warm compress can be
used several times a day to treat this.

Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.

Results

The
hepatitis C virus (HCV) test is a blood test that
looks for the genetic material (RNA) of the hepatitis C virus or for the proteins (antibodies) the body makes against HCV.

Results of hepatitis C virus testing that show no infection are called
negative. This means that no antibodies against HCV or HCV genetic material was
found. Results are usually available in 5 to 7 days.

Hepatitis C virus tests

Normal (negative):

No hepatitis C antibodies are found.

No hepatitis C genetic material (RNA) is
found.

Abnormal (positive):

Hepatitis C antibodies are found. A test to detect HCV RNA
is needed to determine whether the infection is current or occurred in the
past. If HCV RNA is found, genotyping can determine which strain of HCV is
causing the infection.

Hepatitis C RNA is detected. This
result means a current hepatitis C virus infection.

What Affects the Test

Many conditions can change HCV
antibody levels. Your doctor will talk with you about any abnormal results that
may be related to your symptoms and past health.

Your results
may need to be rechecked if you are taking some herbs, supplements, or other alternative medicine products.

What To Think About

There is no vaccine to prevent
infections with the hepatitis C virus.

Hepatitis
antibodies can take weeks to develop, so your results
may be negative even though you are in the early stage of an infection (false-negative).

All donated blood and
organs are tested for hepatitis C before being used.

Other tests
that show how well the liver is working are usually done if your doctor thinks
you may have hepatitis C. These may include blood tests for bilirubin, alkaline
phosphatase, alanine aminotransferase, and aspartate aminotransferase.

Many
states require that some types of hepatitis infections be reported to the local
health department. The health department can then send out a warning to other
people who may have been infected with the hepatitis virus, such as those who
are close contacts of someone who has hepatitis C.

A home test kit
is available for hepatitis C (HCV). The kit contains a sharp instrument
(lancet) that you use to draw a small sample of blood from your fingertip. The
blood sample is then placed on a piece of collection paper and mailed in a
prepaid envelope to a lab for testing. Results are available in 10 days. You
are given an identification number to use when calling a toll-free number to
obtain confidential results. If the results of the test are positive, it is
important for you to make an appointment with your doctor to
confirm the test results, determine the amount of damage to your liver, and
determine whether antiviral therapy is an option.

Other Works Consulted

Centers for Disease Control and Prevention (2003).
Guidelines for laboratory testing and result reporting of antibody to hepatitis
C virus. MMWR, 52(RR-03): 1–16. Available online:
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5203a1.htm.

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